6-Hydroxy-5-[(2-hydroxy-3,5-dinitrophenyl)azo]-2-naphthalenesulfonic acid sodium salt

Preparation

2-Amino-4,6-dinitrophenol diazotization, and 6-Hydroxynaphthalene-2-sulfonic acid coupling.

Properties and Applications

dark red light brown. Soluble in water for purple. In concentrated sulfuric acid for red, orange precipitation after dilution. Dye aqueous solution to join concentrated hydrochloric acid have orange brown precipitation; Join concentrated sodium hydroxide solution have brown light purple precipitation.

Standard	Ironing Fastness	Light Fastness	Fulling		Persperation Fastness	Soaping	Water
			Alkali	Acid
ISO	4	6	4		4-5	5	5